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SHOU-NAN LI, JUNG-NAN HSU & GEN-HOU LEU, Industrial Technology Research Institute, CESH, Chutung, Taiwan
KIREL TANG & CHUNG-LING CHIU, BOC Edwards, Toufen Town, Taiwan

ABSTRACT

An improved technique has been developed to determine the destruction and removal efficiency (DRE) of point-of-use abatement systems (called local scrubbers). In this improved method, the DRE value is calculated using the exhaust gas mass flow rates. To determine the mass flow rates, the volumetric concentrations, measured by two Fourier transform infrared absorption spectrometers, as well as air temperatures, pressures and volumetric flow rates, are required. During field studies at semiconductor fabs, the DRE values of a thermal processing unit (TPU) were obtained for two W-CVD processes. The DRE values of the TPU were measured to be greater than 99% for all detected exhaust gases except CF4. For CF4, the DRE was 92% when the TPU was optimised.